The present thesis consists of an edition of an Iranian literary work whose theme is a journey to the Other World, namely the Ardāy-Vīrāf Nāma. The version of this work which is here edited and commented on is a prose version in the Zoroastrian Persian language. A discussion about Iranian conceptions of the Other World is also an integrated part of the thesis. The text of the Ardāy-Vīrāf Nāma is edited employing a text critical method by using six manuscripts. The oldest manuscript, which has been used as the base manuscript for editing the text, was written in 896 A.Y. (Yazdgirdī)/1527 A.D. The edited text is also translated into English, and followed by a Commentary on names, unusual words and Zoroastrian terms used in the text. Other Iranian documents about journeys to the Other World are studied in this thesis as well, and all are compared to the Ardāy-Vīrāf Nāma. The Zoroastrian Persian version of this work is also compared to its Parsig version. The differences between the Zoroastrian Persian and the Parsig versions indicate that they have their background in two different world views. To prove this theory, some significant elements in the Zoroastrian Persian version, which demonstrate that this is a pre-Zoroastrian epic narrative, have been compared to some elements in the Parsig version that show that this is a religious Zoroastrian account. Possible reasons for the change in Ardāy-Vīrāf Nāma from a pre-Zoroastrian epic narrative into a Zoroastrian-religious one are also suggested. A king named Davānūs is one of the Ardāy-Vīrāf Nāma personages. In an appendix, the historical personality of Davānūs is discussed with reference to Arabic, Persian and Greek historiography.